A variety of wood preservation formulations exist including those which contain a biocidal cation, such as copper, and another compound, including an ammonium compound.
J. A. Butcher et al., in New Zealand Journal of Forestry Science, Vol. 9, pp. 348-358 (1979) describe various unmodified and copper-modified alkylammonium compounds as wood preservatives. The copper-modified species included benzalkonium chloride:cupric chloride, octyldecyldimethyl ammonium chloride:cupric chloride, and cocodimethylamine acetate:cupric acetate.
J. A. Drysdale in New Zealand Journal of Forestry Science 13(3), pp. 354-363 (1983) revealed that copper and dimethylalkylamine salts showed some initial improvement over an amine salt alone. However, in most cases, soluble copper salts, which are often acidic, are too corrosive to add to wood treatment mixtures.
U.S. Pat. No. 4,929,454 of D. M. Findlay et al. describes a system which comprises an aqueous ammoniacal solution of copper and a quaternary ammonium compound which contains an anion to solubilize the quaternary ammonium compound. Such anions as hydroxide, chloride (which is preferred), bromide, nitrate, bisulfate, acetate, bicarbonate and carbonate, formate, borate and fatty acid salts are enumerated. Copper is fixed (i.e. fastened) in the treated wood by decomposition of the tetraamine copper (II) complex that forms during preparation of the ammoniacal copper treating solution.
Wood preservation formulations comprising a biocidal cation, such as one comprising copper, and a polyamine, such as a diamine, are described in U.S. Pat. Nos. 4,761,179, 4,857,322 and 5,276,029 to R. Goettsche et al. In U.S. Pat. No. 5,276,029 certain formulations are used which comprise copper carbonate and ethoxylated coconut fatty amine.
An ammoniacal copper-quaternary ammonium compound formulation was reported to prevent decay by P. placenta at 4 kg/m.sup.3 of ACQ (2.1 kg/m.sup.3 copper oxide). See K. J. Archer et al., "A Proposal to AWPA Committee P4 to Include Ammoniacal Copper Quat, ACQ Type B in AWPA Standards", American Wood Preservers' Association Treatments Committee P4, American Wood Preservers' Association Proceedings, 1990.